Such methods of detecting an object are used, for example, for a presence control or for detecting moving objects. Such methods can in particular be used in industrial processes in order e.g. to detect articles transported on conveyor belts.
The problem can occur in this respect that e.g. dust particles are present in the air between the object to be detected and the light source and reflect the pulses of transmitted light transmitted by the light source.
A reflective dust particle can be incorrectly identified as an (additional) object, which may result in the triggering of an unwanted switch signal. It can also occur that an incorrect distance is then associated with the object actually to be detected.
Dust or dirt particles can be understood, for example, as any particles suspended in the air such as pollen, abrasion particles and the like.
A reliable suppression of the incorrect recognition of such dust and dirt particles can in particular frequently not be achieved under the premise of a high spatial resolution which is accompanied by a powerful focusing of the transmitted light transmitted by the light source and under the condition of high sensitivity.